In humans, premature birth or preterm birth refers to birth at a gestational age of less than 37 weeks. Premature birth is one of the leading causes of infant deaths worldwide. Infants born prematurely are also more likely to suffer from various complications both in short term and in long term, including disabilities and impediments in growth and mental development. While substantial progress has been made to improve the survival rate and subsequent development of infants who were born prematurely, the precise cause of premature birth is yet to be fully understood. Given the prevalence and implications of premature birth, there exists a need for new methods to more accurately detect an increased risk of premature birth in pregnant women, such that preventive measures may be timely taken to reduce or eliminate the chances of premature birth. This invention fulfills this and other related needs.